Tote Travel Bag

I have to wear A3 sketchbooks to college and take a separate case portfolio is a cause discomfort travel. Anyone know where I could get a bag that I could get books on A3? I have a handbag because it fits exactly but it is beginning to crumble. Any response would be great:) I go to a school quite rubbish management grudge me, even I get a small scholarship. Also plastic bags tend to wear out very fast with the weight.

I have a large leather bag Radley handbag through eBay with notebooks A3. You may choose a bag of material not wear out so badly?